In This Article
- Apple Watch 4's new EKG app can accurately flag atrial fibrillation 99% of the time when it can get a reading, according to a study submitted by Apple to the Food and Drug Administration
- Atrial fibrillation prevents parts of the heart from beating together, which can lead to higher risks of stroke and heart failure. Early detection is crucial for treatment
- However, the app's positive predicative value, the likelihood that an alert is accurate, is about 45 %
Apple Watch 4's new heart monitoring app can accurately detect atrial fibrillation 99% of the time, according to a recent study submitted by the company to the Food and Drug Administration.
Sekar Kathiresan, MD, director, Center for Genomic Medicine, who studies genetic risk factors for cardiovascular disease at Massachusetts General Hospital, emphasizes the importance of detecting the disease early.
"It's an important disease," he says. "As far as heart rhythm disturbances go, it's the most common. It's a condition where, often, the first presentation is stroke. And it's a condition that if you catch it early, there's an effective treatment—blood thinners. In many ways, it's kind of an ideal scenario for a screening test."
Atrial fibrillation affects patients so that parts of their hearts don't beat together, which can lead to a higher risk for stroke and heart failure. Though early detection is important, the watch isn't always accurate. Dr. Kathiresan calculates that the EKG app's positive predictive value, the likelihood of a problematic reading to be correct, is about 45%. This doesn't just apply to atrial fibrillation.
"For even a very accurate test in a condition that is [uncommon], most of the tests that are going to come back will be false positives," says Dr. Kathiresan.
Many current Apple Watch users, especially younger people, are not likely to have atrial fibrillation, but might still receive problematic readings. Dr. Kathiresan predicts that doctors need to be ready for the influx of users seeking medical advice when they receive irregular heart rhythm alerts.
Learn more about the Center for Genomic Medicine
Learn more about the Kathiresan Lab